Valid Monday August 29, 2016 to Friday September 09, 2016
US Hazards Outlook
NWS Climate Prediction Center College Park MD
EDT August 26 2016Synopsis
: At the start of the period, a
tropical disturbance is expected over the eastern Gulf of Mexico. This system
is currently anticipated to move slowly northwestward then drift
north/northeastward towards the eastern Gulf Coast and the southeast states.
Upper-level low pressure is anticipated over parts of the southern Plains Aug
29-30. Upper-level high pressure is predicted over the west-central U.S. for
much of the assessment period. Surface low pressure near the Alaska Panhandle
early in the period is forecast to bring unsettled weather to the region, while
later in the period surface low pressure is expected over the Aleutians. During
week-2, upper-level low pressure is anticipated over the western U.S. while
upper-level high pressure is expected over the central part of the nation.
Detailed Summary For Monday August
29 - Friday September 02:
- Heavy rain for parts of the Tennessee Valley,
southeast and Mid-Atlantic, Mon-Fri, Aug 29-Sep 2.
- Heavy rain for parts of southern Texas, Mon-Tue, Aug 29-Aug 30.
- Much above normal temperatures for parts of the Northern Rockies and
Northern Plains, Mon-Tue, Aug 29-30.
- Flooding possible, occurring or imminent across portions of the Great Lakes
and the Mississippi Valley.
- Slight chance of much above normal temperatures for parts of the Northern
and Central Plains, Upper and Middle Mississippi Valley, and Great Lakes,
Sat-Sun, Sep 3-4.
- Moderate chance of much above normal temperatures for parts of the Northern
and Central Plains, and Upper Mississippi Valley, Sat, Sep 3.
- Severe Drought across parts of the eastern U.S., Great Plains, northern
Rockies, Great Basin, Arizona, California, eastern Oregon, and Hawaii.
Early in the period, a tropical disturbance is
forecast over the eastern Gulf of Mexico. The disturbance is expected to drift
northwestward then north/northeastward towards the eastern Gulf Coast by Sep,
1, and over the southeast Sep 2. This leads to expected heavy rain (in excess
of 1 inch in 24 hours) for parts of the Tennessee Valley, southeast and
Mid-Atlantic Aug 29-Sep 2. The exact track and strength of the tropical
disturbance are highly uncertain at this time and additional impacts (flooding,
isolated tornadoes, high winds, significant waves, beach erosion, etc.) are
possible for parts of the southeast and Gulf coast. In addition, parts of
Louisiana are currently experiencing flooding so that additional heavy rainfall
would extend and exacerbate flooding concerns, although the heaviest rain is
currently expected to fall to the east of where the most serious flooding is
occurring. Please consult the latest advisories from the National Hurricane
Center at http://www.nhc.noaa.gov/.
A mid-level trough is forecast to move westward across southern Texas. This
leads to anticipated heavy rain (in excess of 1 inch in 24 hours) for parts of
southern Texas Aug 29-30.
An amplified ridge over the interior western CONUS leads to a forecast for
much above normal temperatures (positive anomalies of 10-12 degrees F) for
parts of the Northern Rockies and Northern Plains Aug 29-30.
Monsoonal flow is expected to cause locally heavy rain for parts of the
Antecedent rainfall, in combination with additional rainfall expected
during the period leads to flooding possible, imminent, or occurring across
portions of the Great Lakes and the Mississippi Valley.
Despite dry fuels over much of the western CONUS, wind speeds are forecast
to lessen so that critical fire weather conditions are not currently
anticipated early in the period. Later in the period, model uncertainty is too
large to specify a hazard shape.
A tropical system expected to develop over the eastern Pacific may approach
Hawaii late in this period or early in the week-2 period. Please consult the
latest advisories from NHC at http://www.nhc.noaa.gov/ and the Central Pacific
Hurricane Center at http://www.prh.noaa.gov/cphc/. For Saturday September 03 -
Friday September 09:
During week-2 the circulation pattern is expected to
feature a trough over the western CONUS, a weak ridge over the central states,
and a weak trough just off the Mid-Atlantic coast. This circulation pattern
favors below normal temperatures over the western CONUS. Anomalous southerly
flow leads to a slight risk of much above normal temperatures for parts of the
Northern and Central Plains, Upper and Middle Mississippi Valley, and Great
Lakes Sep 3-4 and a moderate risk of much above normal temperatures for parts
of the Northern and Central Plains, and Upper Mississippi Valley Sep 3.
The tropical disturbance currently northeast of Cuba of Haiti may be
impacting parts of the southeast and Mid-Atlantic early in the period but model
uncertainty precludes the specification of hazard shapes at the current time.
The Atlantic is showing increased tropical activity and this evolution will
need to be monitored. Please consult the latest advisories from the National
Hurricane Center at http://www.nhc.noaa.gov/.
According to the U.S. Drought Monitor, the coverage of severe or greater
drought decreased slightly to 7.41 percent from 7.71 percent. Improvements were
realized across central Texas and the Tennessee Valley.
Click here to see a display of the GFS Ensemble Forecasts
Please consult local NWS Forecast Offices for short range forecasts and region-specific information.